Cap. plague in Minolta DiMAGE Scan Elite 5400?

[philpem]

Hi guys,
I'm trying to fix a Minolta DiMAGE Scan Elite 5400 film scanner. When powered up, the light blinks slowly (as it should), the software can see it, but as soon as it tries to start the "startup dance" (i.e. pull the mechanism into a sane starting position), the light turns either solid on or solid off, the PC software locks solid, and... well... that's it. You can unplug the scanner (USB or power) and the PC software will suddenly spring back to life and whimper about the scanner being unplugged, but that's it.

I've had the thing open this afternoon -- as far as parts go, it's the usual story -- loads of custom LSIs and not much else. There are, however, a couple of "TACON" 470uF capacitors dotted around the motherboard, and about a dozen or so tin-can SMD electrolytics of various values. Random ESR tests with my Atlas ESR came up in the region of 0.09 Ohms for the TACONs, and about an ohm for the few tin-cans I tested (it's hard to test SMD parts with the Atlas's standard probes).

Initially I thought the problem was with the power supply for the scanner -- a cheap Maplin 24V piece-of-scrap. Evidently this was not the case, because the scanner still behaves the same way when connected to my "testbench" power supply -- a Densei-Lambda EWS600P-24 (yes, a 600W, 24V PSU -- most definitely NOT a toy).

None of the capacitors are showing signs of leakage or bulging, unless it's happening on the bottom side. I'm tempted to shotgun them anyway, unless anyone has any Minolta scanner repair tips to share that suggest the problem may lie elsewhere?

Tech support and parts are basically NLA for these -- I've got the service manual, but it's basically a "how to remove stuff" book, no schematics, or even troubleshooting info (if light blinks this way, swap board X, etc). Pretty pathetic, really.

Any ideas folks?

Cheers,
Phil.


EDIT: Should have pointed this out -- the tin-can electros have value markings, but no obvious make/model markings. The scanner dates back to 2003 based on date-codes on the PCB and components.

[linuxguru]

Tacon or Taicon? Taicon is a Nichicon subsidiary that makes middle-of-the-road caps, sometimes with specs similar to Nichicon caps of the same series, e.g. HD, HM, etc. It won't hurt to replace them, but 0.09 is within spec for most low-ESR series.

[philpem]

Originally Posted by linuxguru

Tacon or Taicon? Taicon is a Nichicon subsidiary that makes middle-of-the-road caps, sometimes with specs similar to Nichicon caps of the same series, e.g. HD, HM, etc. It won't hurt to replace them, but 0.09 is within spec for most low-ESR series.

Tacon. I know of Taicon (in fact Google kept replacing "Tacon" with "Taicon" in my searches), but couldn't find anything about Tacon (not even an entry on the FC2 capacitor logo database). That's partly why I was somewhat suspicious of them -- usually the decent (or at least half-decent) manufacturers actually have websites...

The Tacon I measured is marked 330uF, and there's one not far away marked 100uF -- I suspect they're wired in parallel and my ESR meter is getting confused... Either that or the Atlas is getting confused with the SMD ceramics I can see on the same tracks.

Problem is I can't prove it either way until I desolder them, and after I do that, I may as well replace with new parts anyway.

[philpem]

Urgh...

Just spent a few hours with the oscilloscope and found *nothing*. The original caps were Taicons, guess I misread the labels. Oops. I swapped them anyway, no change. Also swapped the motor driver chips (there are a few notes in the service manual that imply that Minolta knew something about failing motor drive chips). No change with that either.

I'm working this weekend, so I'm taking a little "working break" from this particular project. However, if anyone who's done troubleshooting work on Minolta film scanners is reading this and would like to share their expertise... either post below, or email me. I'm philpem at gmail.com

At this point, I'm thinking "busted mechanics" (though this seems unlikely, there are only a dozen or so gears and all of them look fine), "busted drive motor" (maybe, but not likely), or possibly "busted motherboard".

It's going through the startup dance (if there's a film holder loaded, it'll eject it) but won't go through white/black level calibration. I've yet to figure out what it's waiting for...

This is so annoying!

-Phil.

[kc8adu]

does the ccfl stay on during the time it should calibrate?

[philpem]

The CCFL turns on when the scanner powers up and stays on all the time.

[BGUERBET]

Did you find the cause of the breakdown ?
I had a similar failure and I found an inflated capacitor near the CI 8 legs (AIC1563CS regulator which is also very hot, probably because of the capacitor that has sunk) at the top of the card ... But I do not do not know how to interpret the value of the capacitor ... It is 4mm in diameter and 7mm high ...
It is written:
1
50G
310
It is not branded

Do you know what is its value in μF nF pF?

thank you for your reply

Bertrand

[Curious.George]

Originally Posted by philpem

Hi guys,
I'm trying to fix a Minolta DiMAGE Scan Elite 5400 film scanner. When powered up, the light blinks slowly (as it should), the software can see it, but as soon as it tries to start the "startup dance" (i.e. pull the mechanism into a sane starting position), the light turns either solid on or solid off, the PC software locks solid, and... well... that's it. You can unplug the scanner (USB or power) and the PC software will suddenly spring back to life and whimper about the scanner being unplugged, but that's it.

Perhaps the obvious (but you haven't stated that you've already ruled it out):

Have you tried installing the software on ANOTHER computer (in case the computer that is hosting it, currently, is terribly hosed) and verifying the EXACT same behavior?

Does the scanner support another interface (e.g., mine support SCSI, as well) that you could exercise to determine if the behavior is in the mechanism/controller?

[BGUERBET]

Originally Posted by Curious.George

Perhaps the obvious (but you haven't stated that you've already ruled it out):

Have you tried installing the software on ANOTHER computer (in case the computer that is hosting it, currently, is terribly hosed) and verifying the EXACT same behavior?

Does the scanner support another interface (e.g., mine support SCSI, as well) that you could exercise to determine if the behavior is in the mechanism/controller?

This scanner only have USB & Firewire6 connexion...

[Curious.George]

Originally Posted by BGUERBET

This scanner only have USB & Firewire6 connexion...

As you didn't answer the question, I assume you don't have a Firewire-equipped machine to use as a host?

Have you tried installing the software on another USB-equipped machine?

(IMO, these are easier "tests" than poking around inside the unit)

[BGUERBET]

My computer is under win7 64 with XP mode for the scanner and was running the original Minolta application.

The scanner worked very well before the failure, both USB and FireWire ... Of course, I tested on another machine directly windows XP ... Without success ...

Anyway, there is a faulty component to replace, so this is the first thing to do before making new investigations, no?

I am just looking for confirmation of the value of the capacitor described above ...
I remember what is written on it:
1
50G
310

150μF 310v? It seems a lot for the little capacitor size
or 31μF 50v? Thats the question !

[mariushm]

aic1563 is a dc-dc converter chip, see http://www.analog.com.tw/ImgShow/DS-1563G-01.pdf
check example circuits in datasheet and compare your parts with circuit.i have hunch it may be input capacitor for the chip... if so this cap must meet some minimum specs like max esr, ripple etc and a 100uf polymer or tantalum is probably meeting those but an 100uf electrolytic capacitor would not, so i guess they probably went with whatever capacitance and voltage rating combo they could fit and meet the requirements.
my guess is 50v rated, 330uf or something like that... though kinda small for such big values. 0G is also code for 4v voltage rating on small caps but usually theres at least a space before or code is by itself on a line... it would be easier to just desolder and measure.

remove that brown "glue" wherever you see it, it's not supposed to be brown. that material had bad chemical formula, as it ages it goes bad and becomes conductive and can short traces and contacts under itself

[R_J]

This Capacitor is 1µ 50v, G series,
311= 2003, november

[R_J]

If you look at the pdf of the ic, this cap. is most likely C3

[Curious.George]

Originally Posted by BGUERBET

Anyway, there is a faulty component to replace, so this is the first thing to do before making new investigations, no?

Sorry, if you look at my original comment (post #8), it was addressed to the OP (philpem) -- admittedly long after his post originally aired!

[BGUERBET]

Originally Posted by R_J

This Capacitor is 1µ 50v, G series,
311= 2003, november

A big thank you to you ... Indeed, the device dates from 2004 and capacitors have on the last line from 308 to 311 which corresponds to a date of manufacture in 2003. The diagram of the integrated circuit also confirms the value . I am going to mount a chemical capacitor of 1uf 50v and I come back to you to tell you if everything is back in order ... Good Sunday ... God bless you and America... Bertrand

[BGUERBET]

Originally Posted by mariushm

aic1563 is a dc-dc converter chip, see http://www.analog.com.tw/ImgShow/DS-1563G-01.pdf
check example circuits in datasheet and compare your parts with circuit.i have hunch it may be input capacitor for the chip... if so this cap must meet some minimum specs like max esr, ripple etc and a 100uf polymer or tantalum is probably meeting those but an 100uf electrolytic capacitor would not, so i guess they probably went with whatever capacitance and voltage rating combo they could fit and meet the requirements.
my guess is 50v rated, 330uf or something like that... though kinda small for such big values. 0G is also code for 4v voltage rating on small caps but usually theres at least a space before or code is by itself on a line... it would be easier to just desolder and measure.

remove that brown "glue" wherever you see it, it's not supposed to be brown. that material had bad chemical formula, as it ages it goes bad and becomes conductive and can short traces and contacts under itself

The brown run is neoprene glue that is next to the winding of a self ... But anyway, the capacitor is dead ... Thank you for your comments ... Bertrand

[BGUERBET]

After replacing the capacitor with a conventional chemical, the scanner works perfectly again. Thank you very much for your help, especially for reading and interpreting the characteristics of the faulty capacitor...
The defect one have less than half its original value...

[josipk]

Hi all,
I bought used Minolta dimage scan elite 5400 and it was ok. Then I accidentaly reversed polarity and after that I cannot switch it on, no lamp blinking.
After reading the article of BGUERBET at this forum I opened the scanner's casing but cannot see any damaged element, also the mentioned capacitor is ok for me. See my image.
As I'm not an expert could someone say me what to do. Is this the end of scanner's life or is there any chance to repair it.
Thank you for your reply
Josip

[josipk]

Does anybody recognize the characteristics of schottky diode 34 30 on the picture (red arrow)? How could I test it?
May be this diode is the solution of reversed polarity problem on Minolta DiMAGE Scan Elite 5400?