NEC PC-FX Laser Pickup HOP-E1

NEC PC-FX Laser Pickup HOP-E1

I’ve been struggling with a weak PC-FX laser for quite some time. What kept me from changing the laser or pickup unit was that having to take the PC-FX apart and put it back together later is something you wouldn’t wish your worst enemy. A complete disassembly can be found here. However, getting close to the drive unit is surprisingly easy if you just follow this guide.

First, you need a replacement laser. I chose the complete pickup unit (Hitachi HOP-E1), which was available for about 15€.

Turn the PC-FX upside down and unscrew the four Security Torx screws. Although they seem to be T12 screws, a T10 driver works just fine.

pcfx_laser02

Then remove both side panels and look at the left side. At the top, you see the three connectors for laser, motor and lid sensor. Remove the front panel by carefully bending the three plastic clips at the left side, then turn the PC-FX around and bend the clips on the right side. I’ve marked the three clips for removing the top panel too in this picture.

pcfx_laser03

Front panel removed:

PC-FX front panel removed
PC-FX front panel removed

Top panel removed (don’t forget to unplug the lid sensor):

PC-FX front top removed
PC-FX front top removed

Unscrew the four Philips screws, unplug the motor cable and carefully lift the CD drive unit. Then unplug the laser pickup cable from the mainboard.

pcfx_laser06

PC-FX CD unit removed
PC-FX CD unit removed

 

PC-FX CD drive unit
PC-FX CD drive unit

Turn around the CD drive unit and remove the plastic case by bending the four marked clips:

PC-FX CD drive unit
PC-FX CD drive unit

Unscrew both Philips screws that hold the glide rod of the laser pickup:

pcfx_laser10

Now is a good time to take a look at the cable of the new pickup. There is a solder blob, virtually a transport lock. If you don’t remove it, the laser won’t work.

Hitachi HOP-E1
Hitachi HOP-E1

Then unscrew the Philips screw on both pickups and exchange the plastic parts. Insert the glide rod into the new pickup and put everything together. Before assembling the panels, I strongly recommend a function check (this is how I noticed that I forgot to remove the solder blob…).

pcfx_laser12

Troubleshooting (2019-06-02)

A quick update to answer some of the questions that I’ve received in the last years:

  • The new laser doesn’t read discs at all.
    Check if the solder blob has been removed. If it didn’t come with a solder blob, you’ve probably bought a used pickup.
  • The new laser is performing worse than the old one.
    You’ve probably bought a used pickup.
  • There is no difference between the old and the new laser.
    Check the disc for scratches, try a different disc or make a good copy with a PC CD-ROM burner at the lowest speed possible.

You must not adjust the potentiometers if you don’t know what you are doing – it could make things much worse. If you really need to adjust them, measure between all three terminals and note down the values. Make only very small adjustments and do not adjust more than one potentiometer at a time / before doing some tests first.

This is a quote from a post by user SamIAm of the Pcenginefx forums. Annotations have been added in square brackets. I have not tested it yet.

Open up your system, find the row of three white potentiometers, and turn the middle one [VR103] 1/8 of a full rotation [45°] counterclockwise. Check and see if it works. If it doesn’t, give it another 1/8 turn (you want to do this as few times as possible). If it doesn’t work after it’s been turned 4/8 of a full rotation, it’s probably not going to work, and you’ll need a new laser.

A close-up of the daughterboard of my PC-FX. The metal shield hasn’t been removed yet. The potentiometers (trimmers), relevant ICs and connectors are labelled.

NEC PC-FX daughterboard (PWA-3387 72933871)
NEC PC-FX daughterboard (PWA-3387 72933871)

There are at least two more variants of the daughterboard where the labels are upside down or some components are in different places.

10 thoughts on “NEC PC-FX Laser Pickup HOP-E1”

  1. Thanks for this guide, really helpful. I too installed a new laser as I was under the impression mine was getting weak – stuttering FMV sequences and disc read error messages.

    After fitting the new laser though, all these issues still remain and nothing has changed. Is there any other part of the console that needs replacing or repairing to get past this?

    1. If the issues remain then it’s probably the game disc. Try to make a copy with a pc and play that…

  2. Thanks for the guide!

    I followed it and installed a new pickup only to find that it became even worse at reading discs. I had to put the old one back in. It reads originals fine but not burns. The new pickup for the most part wouldn’t read either, after all sorts of attempts, spindle adjustment, etc. Maybe I got a crap pickup, it was a Chinese shop on ali…

    I was surprised to see there was no visible screw for changing the laser focus/height/trim/etc. Do you know if there’s no way to adjust the pickup settings?

    Guess I’ll give another go next time I find a pickup for cheap.

  3. This is James from NZ again I am hoping you can help, do you repair NEC PC-FXs or know how to adjust the laser pots?

    I bought one from Japan and it arrived yesterday (paid nearly 400 NZD including shipping). It will not load games and I think something is wrong with the laser? When I try to load an actual PC-FX game or even a burned copy of a game, it just will not load. I can hear the laser going back and forth. It does play normal CDs (but skips) and I did get one game to work, a burned copy of Pia Carrot but only a few times and it heavily skipped during the FMV sections and speech.

    Do you have any idea on what might be wrong or instructions on how to possibly adjust the laser pots>

    Please let me know and thanks in advance.

      1. Hi there, I got a PC-FX a few days ago, and it has some problems reading discs, specially burned ones. I’m looking into adjusting that potentiometer, but the forum you linked is not allowing registration right now, so I can’t access the information.

        Could you post more details about that fix? For example, where the potentiometer is located, maybe some images.

        Thank you!

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