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This Front Loader machine went faulty. On investigation, the Circuit Board AKO 731799-06, BSH 9000449412 , has a blown R71/R72 Resistor. This 2Watt resistor is burnt beyond recognition . Does any one know the value of this resistor, or perhaps a copy of the circuit input power? Where is the best place to get a replacement Circuit Board, or Workshop Manual?
Rest of the board looks Ok, pity to throw this circuit board and the machine away. Machine is hardly used.
ThanksRe: WAS24460 AU/04 FD9109400001- Bosh Washing Machine
if the resistor is on the power input to the board it will prob be about 100 ohms but there is a good chance the switch mode integrated circuit has also gone and the resistor act like a fuse
if it is a power supply fault it can be repaired if you know what your doing
Dave
Re: WAS24460 AU/04 FD9109400001- Bosh Washing Machine
Bosch don’t supply that level of information unfortunately (they probably don’t even have it themselves), they only show the module.
A replacement operating module is about $250 inc. postage.Re: WAS24460 AU/04 FD9109400001- Bosh Washing Machine
electrofix wrote:if the resistor is on the power input to the board it will prob be about 100 ohms but there is a good chance the switch mode integrated circuit has also gone and the resistor act like a fuse
if it is a power supply fault it can be repaired if you know what your doing
Dave
Thank you for your prompt reply. I managed to save one charred/burnt colour band of the resistor and it looks like it was a BLACK band, so a 100 ohms seems about correct and as you said it act as a fuse.
I am handy with this sort of work, have repaired different boards before, but this is a double sided board and a bit hard to trace. What I discovered, is the connection of the active side on the rectifier bridge, is missing. The neutral connection side of the bridge is present. So somewhere between the other side of this burnt resistor and the bridge, lies my problem. Without a circuit diagram it is a bit hard to trace, but I haven’t given up yet.
Thanks againRe: WAS24460 AU/04 FD9109400001- Bosh Washing Machine
qas wrote:Bosch don’t supply that level of information unfortunately (they probably don’t even have it themselves), they only show the module.
A replacement operating module is about $250 inc. postage.Thank you for your reply.
$250, is that Aus or US dollars? Local supplier or UK? Is it a new board or repaired one? Will it be a direct replacement?Thanks
Re: WAS24460 AU/04 FD9109400001- Bosh Washing Machine
That’s AUD from for a new board sourced in Australia.
Re: WAS24460 AU/04 FD9109400001- Bosh Washing Machine
qas wrote:That’s AUD from for a new board sourced in Australia.
ThanksRe: WAS24460 AU/04 FD9109400001- Bosh Washing Machine
the resistor feeds to a bridge rectifier and then to a capacitor which gives dc voltages of about over 300v. this is then fed into a switch mode power suppy. you will find a small 7 leg chip (sometimes 8 ) near the cap close to a small transformer. number normally begin tny but there is another one. look up TNY264 as a ref
if resistors have blow then replace chip and resistors and with a bit of luck it will burst into lifeDave
Re: WAS24460 AU/04 FD9109400001- Bosh Washing Machine
electrofix wrote:the resistor feeds to a bridge rectifier and then to a capacitor which gives dc voltages of about over 300v. this is then fed into a switch mode power suppy. you will find a small 7 leg chip (sometimes 8 ) near the cap close to a small transformer. number normally begin tny but there is another one. look up TNY264 as a ref
if resistors have blow then replace chip and resistors and with a bit of luck it will burst into lifeDave
Thanks your email.The reason that I could not get continuity from the resistor to the rectifier bridge, is because I had the circuit board on the bench and not connected to the machine, when I was tracing for continuity. The resistor connection goes away to the underside of the edge connector ST 11 pin 1 and returns back on pin 3.
The surface mount IS5, the switch mode 7 leg chip, is covered with heavy lacquer and I can only read the last few digits xxxxx04GN, it doesn’t seem to be blown. But before I order a replacement part, is this the same as the TNY264?
Thank you for your help so far.Re: WAS24460 AU/04 FD9109400001- Bosh Washing Machine
cant be certain on that one there are 2 types of chips used in this type of postion cant remember the other but will look around and try and repost later
Dave
Re: WAS24460 AU/04 FD9109400001- Bosh Washing Machine
electrofix wrote:cant be certain on that one there are 2 types of chips used in this type of postion cant remember the other but will look around and try and repost later
Dave
Managed to scrape a bit more lacquer off the chip and it looks like it is a LNK304GN. Data sheet says Link Switch 85-265 ac input and 12V dc out.
Is this correct?Thanks
Re: WAS24460 AU/04 FD9109400001- Bosh Washing Machine
electrofix wrote:cant be certain on that one there are 2 types of chips used in this type of postion cant remember the other but will look around and try and repost later
Dave
Dave,
Thank you very much for your help.Machine is now working again. Replaced Resistor/Fuse and installed an upgraded chip LNK305PN( not the SMD type, had to wire up an 8pin ic socket, just in case the chip blows up again)instead of the original LNK304GN.
Thanks again Dave.Re: WAS24460 AU/04 FD9109400001- Bosh Washing Machine
no probs m8
chips dont go that often so should be ok now
bit cheaper than a new board isn’t it
these chips are becoming quite common so get this fault in other appliances so look out for it
Dave
Re: WAS24460 AU/04 FD9109400001- Bosh Washing Machine
Hi, I too have this same problem with the fuse and chip blown, my only problem is I cannot find the value of the 2w resistor, could you please tell me which one I need? Thankyou in advance, Neil
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