Pickups

Overview

Colloquially also known as the "Laser", while the actual laser diodes only make up for a small part of what goes into a pickup.

Pickup types

Sony

• KHS-400A (A-chassis, some A+-chassis)
  • The first pickup to be used in consumer consoles
  • Almost identical to the more common KHS-400B (T487 type); the only differences are a small mechanical change to the base (see below) and a slightly different design of the plastic cap; all parts of the optical system are identical
    • always is the T487 type

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  Differences between KHS-400A (left) and KHS-400B (earlier type) (right)

• KHS-400B (some A+-chassis, AB-chassis, B/B'-chassis, C/C'-chassis, D/D'-chassis)
  • increases height of a small piece of the metal base so it can activate the home position switch on the motor board in the AB/B/B'/C/C' chassis drive blocks
    • the height of this piece actually was increased once more for D/D'-chassis; see below
  • base assembly exists in 2 main variants:
    • Earlier type, shorter piece at the metal base (but taller than on KHS-400A) that activates the home position switch near the motor spindle (made for A+/AB/B/B'/C/C' chassis, also compatible with A-chassis, but mind the correct type (T487)!, incompatible with D/D' chassis)
    • Later type, taller piece at the metal base that activates the home position switch near the motor spindle (made for D/D' chassis, also mechanically compatible with A/A+/AB/B/B'/C/C' chassis, but mind the correct type (T487 except for late C/C' chassis, which also support T609K)!
  • This pickup exists in 2 main variants:
    • T487: white lens, no violet marking at skew adjustment screw, supported by any chassis compatible with the KHS-400B
    • T609K: yellow lens, or white lens with violet marking at skew adjustment screw, only supported in D/D' chassis and late C/C' chassis consoles (which already have a D/D' chassis MechaCon; C/C' chassis consoles never directly came with a T609K type pickup out of the factory, though)
  • the T487-variant can drop-in replace KHS-400A in A/A+ chassis (this was also done by Sony itself in some A+ chassis consoles), but not vice-versa
  • Different revisions of the FPC (the "circuit-board") on the bottom exist, with some having an amber solder mask and others having a green solder mask. Also, component layout and placement differs between revisions. These differences don't cause any compatibility issues.

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  Differences between the earlier (left) and the later (right) KHS-400B metal base type

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  Demonstration of an earlier type KHS-400B failing to activate the home switch in a D-chassis console

• KHS-400C (F-chassis, G-chassis, H-chassis, I-chassis, PS2-mode laser in all PSX consoles)
  

  A picture showing the height difference between KHS-400B (earlier type) (left) and KHS-400C (right)
  

  KHS-400C of the newer T609K object type. Note the yellow (instead of white) protective ring.
  • Decreases total height of the pickup, to fit into F/G/H/I chassis and PSX/DESR
  • Does technically also fit into A/A+/D/D' chassis, although this was never done by Sony. Some late DTL-T units using the A/A+ chassis drive mechanism were fitted with KHS-400C from the factory. Does NOT generally fit into AB/B/B'/C/C' chassis despite seemingly working at first (will bend and damage the flat flex cable when reaching the outer area of the disc)
  • Different plastic cap styles exist, with earlier ones only having a SONY logo embossed on the top side and later ones also having the model number "KHS-400C" embossed. These differences don't cause any compatibility issues.
  • Different revisions of the FPC (the "circuit-board") on the bottom exist, with some having an amber solder mask and others having a green solder mask. Also, component layout and placement differs between revisions. These differences don't cause any compatibility issues.
  • Exists in 2 main variants:
    • T487: white lens, no violet marking at skew adjustment screw, only supported in F-chassis consoles
    • T609K: yellow lens, or white lens with violet marking at skew adjustment screw, supported by any chassis compatible with the KHS-400C
• KHS-400R (F-chassis, G-chassis, H-chassis, I-chassis)
  • Is actually just a name given by the community to the Sanyo SF-HD7, before it's proper name was known; for further details, see the paragraph about the SF-HD7
  • Some places differentiate between the metal-body variant as "KHS-400R" and the plastic-body variant (and sometimes also the metal-body variant with a full plastic top cover) as "SF-HD7", however, this is also false
• KWS-200A (DVR/DVD-burning laser in earlier PSX consoles)
  • The only pickup in this list which has a skew sensor (little black part on a separate segment of the FPC) which works in conjunction with a skew motor
• KHM-430(A) (K-chassis, L-chassis slim consoles)
  • Is actually just a rebadged Mitsumi PVR-802W and also identical to KHM-430B and KHM-430C
  • Actually not handled as a separate part by Sony, but as a fully integrated component of the KHM-430AAA drive mechanism it is part of (hence the "M" in the name which stands for fully integrated drive mechanisms in Sony's nomenclature)
• KHM-430(B) (M-chassis slim consoles)
  • Is actually just a rebadged Mitsumi PVR-802W and also identical to KHM-430(A) and KHM-430C
  • Actually not handled as a separate part by Sony, but as a fully integrated component of the KHM-430BAA drive mechanism it is part of (hence the "M" in the name which stands for fully integrated drive mechanisms in Sony's nomenclature)
• KHM-430(C) (N-chassis, P-chassis, R-chassis slim consoles)
  • Is actually just a rebadged Mitsumi PVR-802W and also identical to KHM-430(A) and KHM-430B
  • Actually not handled as a separate part by Sony, but as a fully integrated component of the KHM-430CAA drive mechanism it is part of (hence the "M" in the name which stands for fully integrated drive mechanisms in Sony's nomenclature)

Sanyo

• SF-HD7 (F-chassis, G-chassis, H-chassis, I-chassis)
  • Same form factor as KHS-400C and used in the same PS2 chassis as it (minus PSX/DESR), but requires different MechaCon configuration/calibration data
  • Variants with a full and with a partial plastic cover exist. Only the full plastic cover spells "HD7" on it. They are fully compatible with each other, so this does not really matter.
  • Variants with a metal (like KHS-400 A/B/C) and with black plastic base exist. They are fully compatible with each other, so this does not really matter.
  • Several variants of the flex-PCB of this pickup exist, differing in color, routing of traces and even their shape, with some of them contacting the lasercoupler from above and others contacting it from below. They are fully compatible with each other, so this does not really matter.
• SF-DB11 (DVR/DVD-burning laser in later PSX consoles)
  • Several variants exist, of which only some are compatible with the PSX; see above

Oddly enough, the I-chassis service manual also mentions Sanyo SF-HD8, SF-HD9 and SF-HD10, which seem to be very different from SF-HD7 in construction. Never seen in any consumer PS2 console.

Mitsumi

• PVR-702W (J-chassis)
• PVR-802W (download datasheet) (K/L/M/N/P-chassis slim consoles)
  • Identical to Sony KHM-430(A), KHM-430B and KHM-430C, which are all just rebadged PVR-802W pickups

Sankyo/Philips

While Sankyo is confirmed as the manufacturer of the whole drive assembly in consoles using this pickup, the actual pickup might be manufacturerd by Philips, as SPU3170 would be consistent with their naming scheme for pickups and Sankyo was never known to produce pickups, since their expertise lies within electromechanical systems.

• SPU3170 (some K/L-chassis slim consoles)

Third party replacements/clones

• KHS-400H / PS-400H (replaces SF-HD7)
• KHS-400Q / PS-400Q (replaces KHS-400C)
• KHS-400W (replaces KHS-400C)

Laser units

• Pickups in fat consoles (except J-chassis), including the ones made by Sanyo, all use a Sony "Laser Coupler" (combined dual wavelength laser diode + dual wavelength PDIC)
  • There are (at least) two variants of this Laser Coupler: One to be used in T487-pickups (see above) and one to be used in T609K-pickups. It is not known whether the variant used in the Sanyo Pickups is either of these two variants.
    • The difference between these variants lies within the polarization filter stuck to the window; while T487 has a quarter-wavelength-plate installed on the entire area of the window, T609K has a smaller, circular layer of film (probably also a quarter-wavelength-plate?) stuck onto the center of it
  • The first variant of the Laser Coupler is known to have the part number SLK3201PE, thanks to official Sony publications
  • According to a single source, the PDIC inside SLK3201PE has the part number "CXA250BH2"
  • The PDIC of some or all KHS-400C pickups of the T487 type (and maybe also some of those of the T609K type?) has a "A2508A" marking, which would suggest a part number of "CXA2508A"
  • The PDIC of (at least some) late KHS-400B pickups of the T609K type has a "A2657" marking, which would suggest a part number of "CXA2657"

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• All slim pickups (both, those made by Mitsumi/Sony and those made by Sankyo) as well as the J-chassis pickup use a more traditional approach, consisting of a laser diode (dual-wavelength, with power monitoring photo diode) and a separate dual-wavelength PDIC

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  Bottom side of the KHM-430/PVR-802W pickup

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  Laser diode of the KHM-430/PVR-802W pickup

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  PDIC of the KHM-430/PVR-802W pickup

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  Close-up of the laser diode

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  Close-up of the PDIC

Notes

• KHS-400R is an alternative name given to the Sanyo SF-HD7 by the community; it is not an official term
• KHS-400B and KHS-400C are electrically compatible, but differ in thickness of their bases, making them partially mechanically incompatible (putting a KHS-400C in place of a KHS-400B in AB/B/B'/C/C' chassis will seem to work at first, but the flex cable will bend heavily once the pickup reaches the outer area while moving)
• KHS-400C and SF-HD7 are mechanically fully compatible, but require different calibration data for MechaCon (use LensChanger or PMAP)
• There are 2 different types for each of KHS-400B and KHS-400C, which require different calibration data for MechaCon: T487 (white ring around lens) and T609K (yellow ring around lens). T609K seemingly was introduced with the D/D'-chassis. Some very early T609K have a white ring around the lens. These pickups may have a violet marking at the adjustment screw (Markings in other colors don't indicate any lens assembly variant, only violet does). Alternatively, they might also have "609" hand-written on their base.
  • Until early C-chassis (included), only the T487 type is supported. D-chassis (and some later C-chassis consoles with a D-chassis MechaCon) as well as F-chassis support both types (MechaCon needs to be configured for the installed type, e.g. using PMAP). Starting from G-chassis, only the T609K type is supported.
• KHS-400B (T487 type) can fully drop-in replace KHS-400A, but not vice versa (mechanical reasons: KHS-400A in a drive meant for KHS-400B can't press the home-position switch near the spindle).
• PSX consoles always have 2 pickups: One KHS-400C (for PS2 games only) and KWS-200A (XPD-001 motherboard) or SF-DB11 (XPD-005 motherboard). Every disc will first be detected by the KWS-200A / SF-DB11, so if this pickup is broken, the console also won't read PS2 games, since the KHS-400C only becomes active once a Disc to be read by it has been detected by the other pickup
• The drive mechanisms of earlier and later PSX consoles are completely different from each other (except the KHS-400C), so you can't replace a KWS-200A with a SF-DB11 or vice versa
• PVR-802W and KHM-430(A/B/C) seem to be mostly identical; KHM-430(A/B/C) is probably a rebadged PVR-802W
• Several variants of the Sanyo SF-DB11 pickup exist, with only some of them being compatible with the PSX. Trying to install an incompatible one will (sometimes? always?) burn the flat flex cable and/or blow the 5V drive-power fuse on the motherboard depending on your luck (known compatible variants: bottom sticker number starts with DB11B; known incompatible revisions: bottom sticker number starts with DB11N, 11NX or 11NXL). It didn't seem to damage anything else though; most notably all electronics (after replacing the blown fuse) AND the laser pickup (after being installed into a compatible PC drive that uses this variant) survived.
  • These different types are seemingly actually called "SF-DB11B" (the one compatible with the PSX), "SF-DB11NS", "SF-DB11NX" and "SF-DB11NXL" (all three incompatible with PSX). These are best differentiated by the bottom sticker, not by the embossed revision number on the top.
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  • Comparison of an compatible type (left) with an incompatible type (right) of SF-DB11 with the bottom shielding removed:
    
• There is an official documentation of the KWS-200A used in the DESR-x000 and DESR-x100 PSX, released by Sony itself:
  

Adjustments

The two 2-kOhms potentiometers on the pickups (one for each, CD and DVD) do not directly adjust laser output power. Laser output power is actually regulated in real time by the drive electronics (APC, automatic power control). Instead, these potentiometers adjust the output level of the monitoring photodiode which the drive electronics uses for monitoring the laser output power. Hence, any weakening of the laser output power over time is already being compensated by the drive electronics. This means that adjusting these potentiometers should never be necessary. The only way of properly adjusting these potentiometers would be by using a laser power meter, which would however only be necessary in case someone already tinkered with the potentiometers.

What turning these potentiometers actually does is overdriving the laser to higher than specified output power. The reason why this might allow discs to be read again is that it gives the drive higher tolerance to dirt on or inside the pickup's lens/prism system and/or misadjusted drive mechanics (tilt/skew).

Instead of overdriving the laser diodes (and causing long-term damage to them), the actual issues should be adressed (dirt and dust on or inside the laser, miscalibrated mechanics etc). Mechanical and electrical calibration can be done by connecting to Mechacon from a PC via UART (see Test points) and then using a tool called PMAP.

KHS-400A, KHS-400B and KHS-400C have the current needed for driving the laser diode to achieve the specified light emission printed on their labels. E.g. "D565 C668" means 56.5 mA for the DVD laser diode and 66.8 mA for the CD laser diode. These values vary for each individual unit and are also based off the condition the laser was in directly after manufacturing, not after decades of use.

SF-HD7 with a metal body also has the specified current written on it's labels. The top/green label has the CD current encoded in the first 2 digits, which can directly be interpreted as the current in mA (no decimal value is given; the third digit is already part of a datecode). The bottom/red label has the DVD current encoded in the 4th and 5th digit, which can also directly be interpreted as the current in mA (again, Sanyo does not give a decimal value, unlike Sony).

SF-HD7 with a plastic body has a single label on it's side, which can be decoded in a similar manner: 4th and 5th digit give the DVD current in mA, 7th and 8th digit give the CD current in mA.