Epson V700 Died Suddenly

[EASmithV]

I was scanning in Vuescan, and all of a sudden my scanner would not respond. I tried to turn it off and on to help reset it, but the power button would not do anything. So I unplugged the scanner and plugged it back in, but the scanner would no longer turn on.
I have been messing with plugging it in and out and letting it sit unplugged various ways. One time the top light came on, but not the power button LED or bottom light. Several times, I have gotten the power LED and bottom light to turn on, but the scanner is not running the heads as it would in a normal startup procedure. More often than not, it will simply not turn on.

Do I have a failed motherboard?! I have confirmed correct power from the power supply with a voltmeter.

 

[Sirius Glass]

In my experience scanners crash and die in the most mysterious ways and without warning. No other camera, device, or consumer item has died in any way comparable to scanner deaths. I just go on line to a company like Epson and order a reconditioned one to save money. The past few years, the most obnoxious weird and bad machine behavior has come from HP in my household.

 

[FotoD]

I had some problems when the cable to the lid disconnected. Took me a while to figure it out. But yours sound more serious. Hope it wakes up again.

 

[Les Sarile]

I was scanning in Vuescan, and all of a sudden my scanner would not respond. I tried to turn it off and on to help reset it, but the power button would not do anything. So I unplugged the scanner and plugged it back in, but the scanner would no longer turn on.
I have been messing with plugging it in and out and letting it sit unplugged various ways. One time the top light came on, but not the power button LED or bottom light. Several times, I have gotten the power LED and bottom light to turn on, but the scanner is not running the heads as it would in a normal startup procedure. More often than not, it will simply not turn on.

Do I have a failed motherboard?! I have confirmed correct power from the power supply with a voltmeter.

Did you test the power supply under a load of about 50ohms since it's a 24V 1.5A from what I can find. Unloaded, the power supply may seem like it's working but can fail when plugged in.
If you can get to the innards testing the voltage on the other side of the switch would verify the PS under load and switch.

BTW, there was a recent post on this forum and the author shows a complete breakdown to get to the innards that may be helpful -> Epson V700 scanner repair. A comedy of errors.

 

[loccdor]

You may just want to purchase an old Epson 4490 for around $50. It's what I did when my Epson failed due to a dead bulb.

 

[koraks]

Do I have a failed motherboard?! I have confirmed correct power from the power supply with a voltmeter.

Still sounds more like power supply issues.
A 3rd party replacement should be cheap enough to give it a shot.

https://www.amazon.com/Compatible-B11B178011-Perfection-Replacement-Switching/dp/B00GU7MLR2

 

[EASmithV]

I ordered a new power supply, because the old one did seem to be an issue. It made some noises and then died again.

Following the other post, I found the service manual and I took the scanner apart and examined the main board. I didn't see any glaring issues, and the only problem that I could see at all was a POTENTIAL capacitor leak. I tried to test it with my multimeter, but literally none of the capacitors on the board register the way they are supposed to, so I think I must be doing something wrong??

Half of the issues in the Epson service guide call for main board replacement as a repair, but all thier parts suppliers seem to be OOS which is amazing because it seems to be the same mobo as the 750 and possibly others.

Getting a 4990 may be the easy option, but that's pretty damn sad that I have to downgrade because my nicer & newer scanner simply died without all *that* much use. I'm averse to upgrading because not only are the V850s extraordinarily expensive, but I feel like there is no guarantee that one of them wouldn't brick itself in this manner and also lack replacement parts.

 

[Bushcat]

To test capacitors in-circuit, you need an ESR meter rather than a standard multimeter. A really cheap one should be good enough for a go/no-go indication. I think this uses a 24V power brick: as a quick sanity check, a 19V notebook power adapter (but not a Dell one) might let the scanner show signs of life.

 

[koraks]

I tried to test it with my multimeter

There's really no good way to test individual capacitors while they're part of a circuit.
A dead cap can indeed match the problems you're seeing with this unit.

Can you post a photo of the affected capacitor(s)?
Generally, dealing with suspect electrolytic capacitors consists of simply replacing them. This can be challenging if they're SMD ones, but through-hole ones are pretty easy.

 

[Alan Edward Klein]

I may have missed it. But did you call Epson to find out if it can be repaired and how much?

 

[4season]

Although your scanner's symptoms sound a bit different, I was experiencing occasional problems with my V700, where the scanner head would seem to get stuck in a loop and make chattering noises. At first, powering things down seemed to fix it, but it became worse, until scanner was unusable.

For want of a better idea, I popped open the lid assembly (I had gone over the main scanner previously), wiped down the silver bar with a clean rag, then applied a thin coating of lubricant, wiping away excess until it looked clean and dry. Removing silver bar entirely, I also applied some lubricant directly to the scanner head's sintered-bronze (oilite) bearing. This sort of bearing is kinda supposed to be lifetime-lubricated, but in practice, they do dry out eventually. That the original lubricant outgasses is pretty obvious, because the inside of the scanner glass tends to get a bit foggy over time.

With scanner head disengaged from the drive belt, the head assembly should glide with very little friction.
No worries if the head becomes separated from the toothed drive belt, as the latter is simply pressed into place, and exact position on said belt doesn't seem to matter much.

Scanner's performance has been flawless since servicing.

 

[EASmithV]

There's really no good way to test individual capacitors while they're part of a circuit.
A dead cap can indeed match the problems you're seeing with this unit.

Can you post a photo of the affected capacitor(s)?
Generally, dealing with suspect electrolytic capacitors consists of simply replacing them. This can be challenging if they're SMD ones, but through-hole ones are pretty easy.

Here's a the capacitor that I think is the problem.

I ended up taking a risk on an untested V800 for $200, and thankfully it seems to work just fine, but I'm still interested in getting this V700 back to life at some point. At least it can potentially be a parts unit for shared things like the glass, stepper motors perhaps.

 

[koraks]

Here's a the capacitor that I think is the problem.

I don't see anything odd about it. The crud on the bottom of the PCB is just dried remnants of flux.
You could still replace it, see if makes a difference. It's a $0.25 component and a 5 minute procedure, so it might be worth the gamble.

I ended up taking a risk on an untested V800 for $200, and thankfully it seems to work just fine

Good job!

 

[Alan Edward Klein]

Here's a the capacitor that I think is the problem.

I ended up taking a risk on an untested V800 for $200, and thankfully it seems to work just fine, but I'm still interested in getting this V700 back to life at some point. At least it can potentially be a parts unit for shared things like the glass, stepper motors perhaps.

Who sold a V800 for $200 that works?!?

 

[EASmithV]

Who sold a V800 for $200 that works?!?

Ebay score from a random used computer reseller, I talked him down from $300 to $212 shipped, since it was an as-is risk. It now sits next to the Coolscan 4000 I found in a dumpster

The only downside? It has ALL the dust inside, i'm gonna have to do a teardown just to clean it. In fact, maybe someone got so tired of dusting scans that's why they unloaded it?

 

[reddesert]

I agree with koraks that there doesn't seem to be anything obviously wrong with the capacitor - the dried flux is not a big deal. A truly blown electrolytic capacitor often has visible issues or smells bad, although a cap can fail without such obvious signs. If I'm reading right, that is a 100 uf 10V capacitor, which is a low voltage rating so it's likely sitting in a 5v part of the circuit. You could always replace it with a 100 uf cap with a higher voltage rating.

Typically, a way to debug electronic hardware is not to try testing individual components in-circuit, which is often impossible, but to test the voltage at various points around the circuit to be sure that DC voltages or signals are appropriate. For ex, near the IC in your picture is a pad labeled "TP10" which is probably a factory test point. Unfortunately, without a service manual or working example, in a complex circuit it's very hard to know what the test point voltages should be.