Bosch SHU43 problem

[JohnF]

I have followed the advice on this forum. Very helpful, but I am stuck. I found the burnt solder joint on the circuit board. I resoldered it. Does not seem to have fixed the problem. The machine just runs and runs.

If you have a burnt solder joint, do you need to get a new board?

I measured internal temp. About 160 degrees. So I know that the heater is working.

I have the clean light always on. Which leads me to a bad NTC, but I do not get the other symptoms on diagnostic that the NTC is bad. It says that the pump will stop shortly after test mode starts. It does not. It just keeps running.

Anybody have any advice?

[jeff1]

Hi,

If you have a burnt solder joint, do you need to get a new board?

Most times yes.....esp if under the 5 year parts warranty!

jeff.

[JohnF]

Unfortunately, I am out of warranty.

Since the heater was working when I measured the temp last night 160 degrees, and it still had the same problem would you think the temp sensor is defective?

Or should I start by buying the replacement circuit board?

[jeff1]

A test that may help....

http://www.applianceaid.com/boschDW.html

jeff.

[JohnF]

I tried the test

"If NTC probe (f2/f4) has failed (opened), CLEAN light will come on immediately and testing will end shortly after water has started circulating."

The clean light is on for the duration of the test. But the test does not stop. It just keeps on going.

That is what I do not understand.

[jeff1]

Another NTC test....Normal resistance is approx. 50K ohms @ room temperature. Resistance decreases as temp. increases.

If ok, sounds like new control time.

jeff.

[JohnF]

OK, I checked the resistance on the NTC. Temperature of water in bottom of dishwasher was 70 degrees. Resistance was 63.7K ohms. Is that close enough to spec? Or does that mean NTC is bad. I am not sure how big a range is acceptable.


Thanks for the help!!

[jeff1]

-Sounds- too high to me....might be worth replacing. + or - 5% is usually ok.

jeff.

[jamesc]

I have a similar issue - water not hot and runs forever, had to replace the control module cover - then this issue with low water temp and runs forever. looked at the circuit brd and it had a burnt solder joint, reheated but still not running correctly. My delima is do I change the heat or the control pcb firts? Any suggestions are appreciated..

[jeff1]

Hi,

My delima is do I change the heat or the control pcb firts?

My guess, control board.

jeff.

[BenLasher]

First post. Great site!

I am running the test on my SHU4306. How long will it run? It has probably been 30 minutes so far.

Does it run a full cycle?

[BenLasher]

Oops. Nevermind. Test just finished. I've got a Wash light (heater fault), and the same symptoms as decsribed in several spots on this forum (long cycle time, low heat).

Will take a look at the control module now.

[BenLasher]

I've got a burnt pin on the circuit board, in fact the exact burnt area as shown in the ApplianceAid Bosch D/W site. Thanks Jeff.

Couple questions:

1) I don't see any two wires (or anything) available to soldier as mentioned in other posts. Is there a way to repair it?

2) Assuming I need to order a board, do I order Repair Clinic item #467087 ? Looks like that part is the two boards inside the full plastic cover. Is there a part number for just the main board?

3) I have a jumper on the Southwest corner of the board (as viewed the same way as on the example picture on ApplianceAid Bosch page. I don't see it on any of the pictures or part diagrams. Do I transfer that jumper to the new board or not?

[jeff1]

Hi,

SHU4306

That is part of a full model#.

I don't see any two wires (or anything) available to soldier as mentioned in other posts. Is there a way to repair it?

Sometimes can clean up and resolder the pin spot.

Assuming I need to order a board, do I order Repair Clinic item #467087 ? Looks like that part is the two boards inside the full plastic cover. Is there a part number for just the main board?


Very possible that is the correct one for your model, the boards are inside a plastic cover and the boards do not come without the cover.

http://www.repairclinic.com/dbimages/00000359/00109405.jpg Control module (http://www.repairclinic.com/referral.asp?R=153&N=467087)

I have a jumper on the Southwest corner of the board (as viewed the same way as on the example picture on ApplianceAid Bosch page. I don't see it on any of the pictures or part diagrams. Do I transfer that jumper to the new board or not?

Yes, transfer it.

jeff.

[BenLasher]

I think the full model # is SHU4306 UC/06. Does that look right?

Maybe I'll try resoldering, but will be prepared to order a new board.

Part # (from PartStore.com $123.00) looks like:
Bosch Part Number: 264461
Bosch Model: SHU4306 UC/06 (FD 7705-7912)
<TABLE border=0><TBODY><TR id=details_all><TD vAlign=top>
CONTROL UNIT + DUD19</TD></TR></TBODY></TABLE>
Part # (from Repairclinic.com $167.40) looks like:
Item #467087

[jeff1]

I think the full model # is SHU4306 UC/06. Does that look right?

Looks right :)

Control module (http://www.pcappliancerepair.com/cgi-bin/promote-detail.cgi?affiliate_id=AppAid&item=264461&brand=BSH)

Maybe I'll try resoldering, but will be prepared to order a new board

Sounds like a good idea.

jeff.

[BenLasher]

Pulled the circuit board last night. Cleaned off the burnt pin with a little piece of emery cloth. Touched it up with a soldering iron and some fresh solder.

Ran the DW through a cycle.

VOILA!

Back to a 90 minute cycle, with clean dishes, and a lot of heat coming from the unit during the dry cycle.

THANK YOU.

[jeff1]

Thankx for the update! :)

jeff.

[Elite Appliance Service]

OK, I checked the resistance on the NTC. Temperature of water in bottom of dishwasher was 70 degrees. Resistance was 63.7K ohms. Is that close enough to spec? Or does that mean NTC is bad. I am not sure how big a range is acceptable.


Thanks for the help!!


The normal reading for the negative thermal coefficient sensor is 55k Ohms at approximately 72 Degrees F. If you have soldered the heater relay your next step will be to verify relay operation. ffice:office" /><O:p></O:p>
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With the outer door panel removed you can either run the unit in a test mode or have it run through a quick wash cycle. Follow the wire harness running down the outer door from the control board to the wash system. Locate the thick red wire in the wiring harness. Once the heater relay closes check for voltage from the relay through the red wire. Since you can't remove the wire from the main board while the test is in progress it would be helpful if you had a line Voltage tester. If you have verified the relay is applying voltage to the heating assembly, and you can measure amperage through the heater circuit with an amp meter then you may get away with just replacing the NTC. Your NTC reading is out by more then 10%. I would advise you to replace it. This may be a big undertaking. <O:p></O:p>
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Always remember to preheat the water supply to the Dishwasher before each cycle to prevent relay failures. It will not prevent a NTC failure, but it will save you energy. I have attached a .pdf file for your reference.<O:p></O:p>
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I hope this information has been of assistance <O:p></O:p>