Well, messy mod on something I got off eBay

wilykat · 08/04/2015, 09:57 PM

Well, now what? I got a second TE as a spare, it was listed as non working. I expected the usual, bad caps and blown fuse. What I saw is worse.

/4jfKgOp.jpg
Long exposed wire from + side of the cap touching a diode and metal box. Brown wire also suggest someone used very hot soldering iron

/TKZKiTC.jpg
2 missing caps, lifted or damaged pads, and melted audio out jack

/6aQvPqv.jpg
One cap with long exposed metal touching another metal spot on the PCB, and another cap had pea-sized solder blob that was floating (not connected) to anything.

And lots of mess from flux, it's hard to tell if any of those are from original cap. I was going to get this recapped and LCD modded but there's fair amount of damage I don't think it'd be safe to LCD mod. The caps currently in use, most of them aren't labeled to the brand so I may need to replace all those.

Any other issue you can see that I may have missed?

PS someone go start a change.org campaign to make license a requirement to use soldering iron. When someone's woefully inexperienced tries to do a difficult task like removing SMD caps, they risk destroying Turboexpress. I may have a few hundred hours of experience with soldering and desoldering but removing caps is not my forte, which is why I paid someone to recap my first TE.

SephirothTNH · 08/04/2015, 10:09 PM

Wow that is terrible. Even beyond what you pointed out the soldering is just awful. You should take all the caps off and clean the board. Then do a real cap replacement on it.

Or better yet get a refund unless you paid pennies for it.

wilykat · 08/04/2015, 10:22 PM

Here's an image of the whole board in a much higher resolution: https://i.imgur.com/G9ExTqH.jpg

I paid $120 for it, the body is in very nice shape with minimal scruff like it was adult owned and rarely played with, original LCD works fine (tested it on my other TE), battery cover included and clean contacts in battery bay, and the controller board is fine. It's only the main board that looks bad. If the mainboard is really unsalvageable, I can still sell the rest as spare parts and still get more than $120 total.

I also noticed the heat shrink tubes on the 2 caps aren't shrinked

I can slide the tubes out of place easy.

SephirothTNH · 08/04/2015, 10:37 PM

It should be repairable; it may just take some patience. As long as none of the ICs have been damaged. Some people really should not be doing this kind of work. It's obvious whoever did it had no idea what they were doing.

Did the seller mention any of this? Or was it just sold as non working?

ToyMachine78 · 08/04/2015, 10:54 PM

Damn! Look at all the rust and oxidation! That thing was kept in Grndmas basement for decades!

wilykat · 08/05/2015, 12:58 AM

Quote from: SephirothTNH on 08/04/2015, 10:37 PMIt should be repairable; it may just take some patience. As long as none of the ICs have been damaged. Some people really should not be doing this kind of work. It's obvious whoever did it had no idea what they were doing.

The IC and its pins seems to be Ok. I'm still waiting for cap kit from console5 to show up before I try anything. I did check the resistance across fuse after I tweaked the caps so nothing were touching and shorting out, I got infinite up through 300k reading. If it was reading low resistance even with blown fuse, it would have indicated problem.

QuoteDid the seller mention any of this? Or was it just sold as non working?

Said it wouldn't power up at all. His account has around 1700 feedback rating with only 1 neg (over 6 months ago) and sells mainly video games. I think he's a reseller who gets em local or runs a game store and just happened to get a dead unit.

wilykat · 08/05/2015, 02:00 AM

I removed all of the old caps (including the 2 original caps associated with LCD) and it's nasty, there were lots of little metal pins still in solder, like someone didn't completely remove all of the old caps. The solder also smelled funky, I am wondering if the solder used was not intended for electronics?

I'd need to know how C101, C102, C103, C104, and C501 is supposed to connect. C501 is the one touching metal box and diode, I can't see where the + lead is supposed to go anymore! The rest still has enough obvious trace or pad left that I can still use them. Wishing there is a good schematic of Turboexpress or GT for me to figure out the caps!!

PS if you are reading this and is the one who did this mod, do me a favor? Use a fucking axe next time. It's like a doctor using industrial chainsaw for circumcision, a police using bazooka to stop runaway criminal, or gardener using a backhoe to plant tulips.

SephirothTNH · 08/05/2015, 02:19 AM

It's hard to explain exactly but did it have a sort of bad fish smell? If so they didn't even clean the leaked electrolyte off the board.

thesteve · 08/05/2015, 02:37 AM

whats scary is ive seen that work before

wilykat · 08/05/2015, 03:23 AM

Quote from: SephirothTNH on 08/05/2015, 02:19 AMIt's hard to explain exactly but did it have a sort of bad fish smell? If so they didn't even clean the leaked electrolyte off the board.

More like smell of trying to re-solder on a 1960's era electronics. I've had bad fish smell in video game but not "very old technology" smell like this on any video game stuff. Even Atari 2600 and Coleco Tristar didn't smell like this when I fixed them.

LostFlunky · 08/05/2015, 07:40 AM

RESOLVED: wilykat and messy modded TE have agreed to stop (in their words) "goofing around" and will attempt to co-exist in the same cosmos.

schweaty · 08/05/2015, 08:59 AM

Quote from: wilykat on 08/05/2015, 02:00 AMI'd need to know how C101, C102, C103, C104, and C501 is supposed to connect. C501 is the one touching metal box and diode, I can't see where the + lead is supposed to go anymore! The rest still has enough obvious trace or pad left that I can still use them. Wishing there is a good schematic of Turboexpress or GT for me to figure out the caps!!

shine a bright light behind the board and follow the traces to a good solder point

100% agree on the sentiment that whoever is doing this shoddy work needs to stop it now.

PCEngineHell · 08/05/2015, 12:56 PM

Wow, just fucking wow. Wonder what kinda iron they used to do that shit. I think you over paid. I'd ask for a refund.

NecroPhile · 08/05/2015, 01:58 PM

I bet it was a hair dryer / soldering iron combo.

ultrageranium · 08/05/2015, 05:35 PM

At least there were no extra layers of hot glue to secure the mod/recap

wilykat · 08/05/2015, 11:17 PM

I managed to clean it up quite a bit with alcohol and I can see more clearly the damage. C704 next to HuC6260 is another problem area for me. The entire trace to + side has completely lifted up all the way under the chip so I would either need to glue that down and solder it together or snip it off and run a wire from the correct IC pin to the cap. Looking at TG-16 schematic, it may be the one that goes to pin 43/46 on the chip.

TG-16 schematic has significantly different sound diagram due to internal speaker and headphone jack. So I'd have to poke around a lot to figure out where those 4 caps belonged to.

GohanX · 08/06/2015, 12:57 PM

Quote from: PCEngineHell on 08/05/2015, 12:56 PMWow, just fucking wow. Wonder what kinda iron they used to do that shit. I think you over paid. I'd ask for a refund.

I've got five bucks that says 45 watt Radio Shack iron.

wilykat · 08/10/2015, 09:41 PM

Good news and bad news:

cap kit from console5 arrived so I got all but 5 installed. One near video circuit at C502, I still haven't figured where the + lead goes. and 4 around audio jack with fouled up pads. The jack fell apart when I was trying to clean brown residue out, I guess it melted too much by the noob idiot so I need to order new jack.

C604 by HuC6260 was another hard spot. The lifted trace had too little remaining for me to tap in. I looked on TG-16 schematic for the same cap connected to 6260 and found it connected to 43 and 46 so I tapped the + lead of the cap to one of that pin. I hope it is the right pin since other cap were checked and I was able to verify correct pins to cap pads. It is only pin 43 and 46 that seems "lost".

Once I figure where the +lead for C502 goes, I can put it back together and see if it works (without sound naturally) and how much more work I'd need to do.

Still wishing someone has Turboexpress or GT schematic so I can fix the sound now. TG-16 doesn't have headphone jack or internal speaker and has different arrangement.

NightWolve · 08/11/2015, 12:20 AM

Quote from: wilykat on 08/04/2015, 09:57 PM/TKZKiTC.jpg
2 missing caps, lifted or damaged pads, and melted audio out jack

Poor thing...

wilykat · 08/11/2015, 05:44 AM

Yes poor thing. It may never play violin again but hopefully I won't have to use the phrase "He's dead, Jim"

I figured out where all the remaining caps are supposed to go in. The + lead appears to go to the tab of D501 on the other side. Next I'll doubl check all the caps to make sure it's soldered in firmly, correct orientation, not touching anything it's not supposed to touch, and no bridges or rogue solder blobs and to check if there's any short between 5v and ground. I still need to clean up the new solder flux and I am out of distilled water so the last step will need to wait. (and still waiting on new jacks, ETA end of August, NEC had to use uncommon design that isn't easily found locally after 20 years)

Also put in a new fuse. All that's left is to plug the LCD panel back and power it on.