Diskwasher won’t start Bosch SGV53E43GB/37 – no lights but has power – control panel?

[PB2020]

Hi
My wife and I have successfully carried out many (basic) repairs on mobile phones, electric showers, toilets, car door locks etc over the years.
The latest challenge we have is our 8-9 year old Bosch SGV53E43GB/37 integrated dishwasher.
Basically set it off one night and came down the next morning to find the cycle had finished but none of the panel lights were on.
Check the plug fuse which was ok. Tried leaving the power off for a couple of hours and switching back on. Nothing.
Opened the door (to gain access to the door internals) and checked the continuity on the power switch. Seems to be working fine and no signs of anything have burned, so tried something else.
This model has a float switch in the bottom of the unit so if it fills up with water, the float switch activates the drain pump. When the unit has power lifting the float switch causes the pump to run so it appears the dishwasher has power.
I suspect a dead control panel esp as no lights come on. A new one is ~£100 (Part Bosch 00644227) and a bit of a gamble, although new dishwasher is £500…
Before i take the plunge – any comments on my diagnosis or anything else i should check first??
Control panel seems to be a sealed unit so i can’t open it and inspect the board….
Many thanks
Paul

[electrofix]

you can open the timer box. opened lots. you need to do this as we need to find out if another component has blown it

Dave

[PB2020]

Hi Thanks. Is the timer box the part i mentioned above (whhite plastic box – Part Bosch 00644227?

If so i’ll remove it again and will see if can open the box…

[electrofix]

PB2020 wrote:Hi Thanks. Is the timer box the part i mentioned above (whhite plastic box – Part Bosch 00644227?

If so i’ll remove it again and will see if can open the box…

correct it all clips together so you have to be careful unlocking the clips but once inside you need to inspect the print for damage

Dave

[PB2020]

Ah brilliant. I’ll have another look this week and report back. Many thanks.

[PB2020]

Ok got into the control box and can’t see anything immediately obvious. Unfortunately can’t seem to upload photos bigger that 19kb which makes my photos too small to see anything. There is a black plastic component with copper wire wrapped aroud it and one leg appears to have no solder when you flip the board over. It also smelt like hot metal when i first removed the baord even though DW has been lef with no power for two weeks….

[electrofix]

upload photos to external site like google etc . Then post a public link

Dave

[electrofix]

how good are you with electronics
and
have you got a multi meter

Dave

[PB2020]

Not great but i can borrow a multmeter…. I am very practical with guidance.

[electrofix]

there is a large green resistor next to the white relay

I am expecting 100 ohm or there about. i need to know if its blown so get the meter and measure it
then let me know
if this works and you or someone you know can do this it could be a very cheap repair

Dave

[PB2020]

Wow. Right!! Is this a common fault?? My neighbour was an electrician and has the multmeter so i’ll speak to him in the next few days. Many thanks

[electrofix]

not uncommon i do quite a few machines with a similar problem

Dave

[PB2020]

Hi OK Have setup MMeter as shown in https://1drv.ms/u/s!AgTs2fMh_4oJgoo_OC0yhZYmRJk6ig?e=SnjubV
When probes touch display drops from 1 to 0.02 – which i udnerstand is the resistance in the leads….
When placed either side of the green resistor it stays at 1.
So if i understand correctly this is possible culptrit???

[electrofix]

well yes and no

the resistor does 2 jobs 1) stops a surge input of current when the unit is plugged in 2) acts as a fuse in case of failure

to hopefully repair it you have to change 2 components

The fusible resistor which looks like 100 ohm fusible
the power regulator chip LNK304GN

cant 100{e5d1b7155a01ef1f3b9c9968eaba33524ee81600d00d4be2b4d93ac2e58cec2d} promise it will work but its over 90{e5d1b7155a01ef1f3b9c9968eaba33524ee81600d00d4be2b4d93ac2e58cec2d} chance of success

https://uk.rs-online.com/web/p/buck-converters/5254167/

https://uk.rs-online.com/web/p/through-hole-fixed-resistors/8558778/

Dave

[PB2020]

Many thanks. I might send the board and bits to a friend who is better at desoldering and resoldering than me…. I’l report back when done.

[Author]

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