After months of repair woes, I have one of my holy grails.

[Vectrex28 | 366]

It all started back when I was still in Japan... I found a classified advertising a broken PC Engine with a few goodies. But not just any PC Engine - the most sought after model: Yes, I'm talking about the PC Engine LT. After some haggling and practicing my Japanese in the process, I had managed to buy it with a few scuffs to my savings. But here it was, not working... Fair enough, I thought. I added it to one of the packages I sent to fellow VGSer @SNESNESCUBE64, thinking it would be an easy repair and... Long story short, all chips in it were fried - So after a few months' worth of soldering and troubleshooting...

Tadaa!

I'm so happy to finally have this legendary model in my hands! Thanks, SNESNES!!!

[DarkTone | 984]

Congrats. Why is it sought after? How many different models are available?

[Splain | 2,569]

Beautiful.

[tbone3969 | 304]

32 minutes ago, DarkTone said:

Congrats. Why is it sought after? How many different models are available?

Why is it sought after.....  just look at that thing.  It's amazing!!!  There are about 10 different NEC systems out there.  Some of them very rare (this one and the LaserDisc unit probably are the rarest).

[Vectrex28 | 366]

This model was basically NEC flexing their technology. Keep in mind this is 1991 technology and quite a few people were wowed by this. However it came with a price (almost 100000 yen) and hence it didn't sell much. And it's even more expensive today if it works properly

[DarkTone | 984]

Nice. A Youtuber I follow reviewed it. Will give it a watch. 

UPDATE. HOLY SHIT! That's really cool! Video made me want to look up more. 

Edited December 9, 2019 by DarkTone

[SNESNESCUBE64 | 537]

I'm happy that this thing is out of my life, it was a hassle in a half, but good experience with the console. 

For future reference here is a few precautionary tips. One, if you have one and haven't recapped it, what are you waiting for! The early 90's were rampant with bad electrolytic capacitors, not a single capacitor hadn't bursted. Whats even worse is that electrolytic fluid leaked under the expansion connector, meaning that I had to desolder it to clean it. I recommend the console5 cap kit for it, their kits are top notch and their customer service folk are great!

Secondly, there is a lot of plastic on this console, so you have to be very careful when using a hot air station to desolder the packages, otherwise you could melt the connectors. Every time I did work, I covered the whole thing in kapton tape to shield it (first picture). Its cheap enough and is very effective. Just as a note, the main card connector as far as I am aware is specific to the LT. I checked both a GT and a core graphics unit, and the connectors were different enough to where it wouldnt work. One thing to note is that you will have to desolder it when replacing the capacitors under it, don't even try to do it without removing it.

One final thing to bear in mind, is that they used epoxy to keep the components on the bottom part of the board in place during the manufacturing process. This makes it a hassle and a half to remove chips on the bottom as just heating the ic and solder may not be enough. I had to desolder the 6264 ram chip on the bottom because it was bad and causing issues, and there were a couple dabs of epoxy.

So anyway, here is the work log of what I did:

 

symptoms: It's dead Jim

No power on the board, no screen, no sound, no boot. Reaked of bursted caps.

Solution: replace the caps, I used a kit from console5. Beer is optional while doing such, I chose Killians Irish Red.

symptoms: I got power, but no boot. Tv function is fine, av in also works

I approached this by looking to see what was happening on the cartridge bus, the address lines were static and there was garbage on the datalines. Nothing obvious. Replaced the 6264 ram chip, nothing significant changed. Although, it did test bad when I put it on a soic adapter and tested it, so it needed to be replaced anyway. Next step, I replaced the CPU, no change. Afterwords, I changed the GPU and the interface chip. PC Engine finally booted.

symptoms: colors were wonky. Green seemed to be stuck at a certain level. (Second picture)

Solution: GPU is bad (ugh I have to replace that dumb thing again). To be fair, it came from a known broken pc engine, so whatever. Replaced it, PC engine was now fully functional.

 

For reference, it shouldn't have taken as long as it did, I just have no free time...

 

Edited December 9, 2019 by SNESNESCUBE64

[Tanooki | 4,933]

Wow that is a thing of beauty both the LT and that hell of a repair job you too. 
 

Remember my groaning nearly a decade ago about no longer having a duo?  I finally jumped back in with a core grafx 2 a couple years back and it’s as amazing as ever so I get it. The Japanese card library is insanely good and a true mark of shame on the US offerings. 
 

I’m currently considering whaling too getting a Duo back but Japanese and totally updated and recapped / repaired too.  I miss my optical memories. I burned a trio yesterday and firing them up in my 20+year old licensed magic engine emulator was a rush!

[Nintendo Historian | 43]

Awesome