Messages

[Console Repair/Mod Center / Re: Leaking ram chip???]

If you need a replacement HSRM2264LM10 it will be just SRM2264LM10 (without the H).

Fortunately the chip is good, so I don't need any replacement, though thanks for the useful info. Could be handy for the future

[Console Repair/Mod Center / Re: PAL turbografx NTSC mod]

and clip pin7 on the cxa1145 and tie it to 5V

Hi all, excuse me for reviving an old thread, but I'll perform this mod in the next few days and the last point of thesteve's post is not entirely clear to me and the links to the pics are broken.

Pin8 of cxa1145 is NTSC/PAL input according to online schematics. Should the pin be lifted and linked to +5V on the lifted chip's leg, and not to the PCB, correct?

Thanks a lot

[Console Repair/Mod Center / Re: Leaking ram chip???]

TG16 back to life. I've rewired the corroded traces, fixed the CPU that had physical damages to some pins, fully recapped the unit. Cool!!

[Console Repair/Mod Center / Re: CD-ROM2 behavior]

The CdRom2 has no anti skip Technology, but once it skips, it should be able to recover the track and the approssimative position. If that does not work for you, it may be due to weak laser (due to wear or aging capacitors) and/or non perfect tuning (could be fixable by potentiometer adjusting)

[Console Repair/Mod Center / Leaking ram chip???]

Hi All,

I'm working on a quite ruined Turbografx16 PAL board that doesn't work. At the moment, before performing advanced tests, I decided to refurbish the board to eliminate all evident problems. The board has been cleaned, one chip with broken legs (mechanical fault made by someone playing with the board) restored, full recap. The board is looking much better now but there are still 5 corroded traces (see 1st pic below). I'll fix the traces but I was wondering where the corrosion came from, as there are no caps in that area. Looking better I noticed that the corrosion happens right under the HuCards bus RAM chip (HSRM2264LM-10), that actually also has a suspecting looking leg (see last picture).

My questions for you guys:
-          Can a RAM chip leak and corrode the traces? It never happened to me before
-          I'll have to desolder the RAM and restore any issues under it, but in the case the chip is faulty I would like to buy a replacement. I'm not able to find any replacement (checked Aliexpress, ebay). Any idea on where to find one?

Any idea or suggestion is very welcome

Thanks!

[PCE/TG-16|CD/SGX Discussion / Re: Help troubleshooting CDROM2]

For future reference to anyone following this thread, I've reached the final stage of fixing my Cdrom2 today by full recapping it and fixing a broken trace on the pcb. At this point the CD-ROM was already able to read audio CDs but skipping tracks even if very gently tapped on the case, so I have also tweaked the pots and it is finally nice and stable

[PCE/TG-16|CD/SGX Discussion / Re: Help troubleshooting CDROM2]

After some more troubleshooting, I've found that the spindle motor is OK but I have found that one of the ribbon cables was inverted (go figure). After plugging from the correct side, the laser beam comes up. I managed to read some audio CD, though the drive struggles a lot. Next I'll recap the whole unit and check if it fixes the problem, otherwise I'll check the pots

[PCE/TG-16|CD/SGX Discussion / Re: Help troubleshooting CDROM2]

I've changed PSU and the problem is the same. I'm suspecting that the spindle motor is gone. Ive done a "soft" test by applying voltage form a battery directly to the spindle motor leads and there's no movement, so I've ordered a replacement motor just in case (waiting for it to be delivered at the moment)

I've also checked the spindle sensor that is activated by the laser block. The sensor is in working order (goes from 1k ohm to 0 ohm when the switch is pressed). Also manually pressing the sensor switch doesn't produce any spindle movement

The caps look fine but of course they're quite old. I'll try recapping for the motor swap doesn't make effect

Any other idea is very welcome

Thanks

[PCE/TG-16|CD/SGX Discussion / Help troubleshooting CDROM2]

I'm seeking for some ideas on how to repair my NEC CDROM2. When I first got it, testing it as a CD player with no briefcase attached, I would only get a 0 displayed on the LCD, but no movement. I have changed the middle gear and greased the spindle. Now the CDROM laser moves correctly and I can hear it focusing, but the CD won't spin.

My ideas are:
- possible PSU not delivering enough power (I'm using an universal PSU)
- broken laser block (how to check for this?)
- needed potentiometers adjusting

Any ideas on how to troubleshoot it?

Thanks a lot for any help

[Console Repair/Mod Center / Re: PCE help diagnose video problem]

today I have refluxed all chips, including RAM and the one on the Hucard doughterboard but the problem is still there. At this point I'm almost sure 6270 is failing

With all those custom chips it's almost impossible to cheap repair the Pc Engine...

[Console Repair/Mod Center / Re: PCE help diagnose video problem]

In the next few days I'll try reflowing anyway, just in case. I'll keep you posted. Thanks!

[Console Repair/Mod Center / Re: PCE help diagnose video problem]

I need to source some flux then I'll surely try refluxing the chips. The problem is that in my case the contacts look perfect to the eye and no short was found with the multimeter. Was the short evident in your case?

[Console Repair/Mod Center / Re: PCE help diagnose video problem]

Any known option to buy a replacement 6270?

[Console Repair/Mod Center / Re: PCE help diagnose video problem]

No shorts detected on 6270. To be honest the chips look in perfect cosmetic conditions, and no bad soldering is evident at all. Would it just be a fried 6270? Does it fail like that?

[Console Repair/Mod Center / Re: PCE help diagnose video problem]

Though I must add that trying different hucards, I always have the same problem: bad palette on sprites and disappearing sprites (meaning possibly that the sprites are there but covered in trasnparent colour, so again a palette problem).

According to the following documentation (http://www.emulatronia.com/doctec/consolas/pce/vdcdox.txt), it is the HuC6260, not the HuC6270 that supplies the colour palette to the Video System. Excluding a problem with the RAM (that would result in far worst effects and also a variety of glitches depending on the loaded game), and despite the fact that the HuC6270 runs hotter than the others, at this point I'm suspecting the HuC6260.

It's also true that HuC6270 does Background character processing and Sprite processing, so it is indeed possible that something is wrong with it...

Any wrong assumptions in what I wrote above? Other ideas?

[Console Repair/Mod Center / Re: PCE help diagnose video problem]

I'll check again very carefully for any shorts in the weekend. Thanks a lot for the tip. I'll keep you all posted

[Console Repair/Mod Center / Re: PCE help diagnose video problem]

Visually I'm not able to see any bridge... Check the attached image

[Console Repair/Mod Center / Re: PCE help diagnose video problem]

Is there any good method of finding if there's a bridged pin? Would checking continuity between pins work even if most of them refer to the same databus or IObus?

[Console Repair/Mod Center / Re: PCE help diagnose video problem]

I have tried with 2 other Hu Cards, and unfortunately I have the same videou output problems. I have noticed that to make the hucard work I had to plug and unplug it a few times. I have also noticed that the 6270 runs considerably hotter than all the other chips. Is that normal?

[Console Repair/Mod Center / Re: PCE help diagnose video problem]

I'll get a couple of new Hu Cards next week. I'll test the unit with the new cards first, then I'll try reflowing. I'll keep you posted guys. Thank you all

[Console Repair/Mod Center / Re: PCE help diagnose video problem]

Today I've completely bypassed the RGB amp by tapping svideo from the EXT slot. Same output.

At this point the chances are:
- broken Hu card
- some strange fault at the RAM level that is not evident with the logic probe

I still have one doubt about the small IC that is located on the Hu Card reader doughter board. Pin 1 seems connected to +5v or GND (I get continuity), but it is the only pin that gives me no reading with the logic probe. Any idea about this?

Also any reference for RAM spare parts?

Thank you all

[Console Repair/Mod Center / Re: PCE help diagnose video problem]

I'm sourcing a few hu cards, so that I'm able to test. If it's not that, my last hope is to bypass the RGB amp completely and see what happens. If that fails too, I may try replacing the RAM, but I have no idea where to get some spares from

[Console Repair/Mod Center / Re: PCE help diagnose video problem]

Today I've checked for continuity ALL the traces going from and to the 3 main chips and the 2 RAM banks, no broken traces found. I've also checked the continuity to and from the HuCard slot, with no issues found. After that I've checked the voltage regulator, and it outputs exactly 5 volts. After that I have checked ALL the chips and RAM pins with a logic probe, and I see pulse to all the RAMbus and DATAbus. I'm really out of clues now. I have tried to bypass the RGB amp, but I'm not sure I managed to bypass it completely, so I can't say if the test was relevant. could it just be a broken HuCard? I don't have another one at the moment for testing. Any other idea to help me?

[Console Repair/Mod Center / Re: PCE help diagnose video problem]

I'll check all the traces as soon as possible. In the case the traces are OK, is there any trusted selled where RAM chips can be sourced?

[Console Repair/Mod Center / PCE help diagnose video problem]

Hi all. This is my first message in the board, and I'm very glad to be part of this community. I hope I'll be able to give help, more than I'll need.
   
On my JPN White PCE (RGB modded) I'm getting corrupted sprites and backgrounds. The characters look fine instead. I'm planning to check the continuity of the traces this weekend because I have a vague suspect for a cut trace between the 6270 and the flat cable. There a bit of solder mask and possibly traces that came off under L102. Could it also be bad RAM?

Any idea or your past experience in similar problems is a very welcome help. All relevant images posted here






Here's an high res pic of the board. The place where I suspect a cut trace is in the lower left part of the image, between L102 and the area where there was the RF unit (removed for RGB mod)


Thanks in adavance for any sugestion