Tyre machine, IGBT and thermistor help

[e5c0rt.mk1]

Hi, bought a tyre machine today, it was sold as spare or repair but its only 3 years old and quite cheap so thought it was worth the gamble.

All the air side of it works, but as soon as I plug it in it blows the fuse in the plug.

Took the top of the motor apart and there is a transistor and thermistor gone bang. Would replacing these get the motor working again or is it likely something else is wrong causing them to burn out.

The part numbers are
RGT60 TS65D
SL32 2R023

Do they have to be the exact same parts or would something of the same spec work as I'm struggling to find any of the transistor at a reasonable price.

Thanks

 

[voipio]

The two resistors, R42 and the one next to it look as if they've suffered, too. There's no guarantee that replacing those parts will fix it, since something else may have caused the problem in the first place, but you may strike lucky.

 

[sako243]

Do they have to be the exact same parts or would something of the same spec work as I'm struggling to find any of the transistor at a reasonable price.

Provided the design is half sensible then something of similar spec will be fine. I caveated that because I've been fixing / working on a system where the original one was so marginal that even modern versions of the old components has caused things to get messy

 

[e5c0rt.mk1]

I have found them from farnell but the handling charges take it to over 20 quid for them, not a dear fix but I don't fancy spending that much on them for them to go bang as soon as I plug it back in.

 

[skotl]

I always thought that IGBTs had to be matched, so it was common to replace them all at the same time?

 

[sako243]

I always thought that IGBTs had to be matched, so it was common to replace them all at the same time?

Only usually if they are being used in parallel. They're a little more complicated than paralleling up MOSFETs (in general you can usually get away with those because they tend to balance each other out if you don't introduce any harmonics).

 

[sako243]

I have found them from farnell but the handling charges take it to over 20 quid for them, not a dear fix but I don't fancy spending that much on them for them to go bang as soon as I plug it back in.

Mouser also have them in stock but the shipping is £12.50 - saves a bit over Farnell.

Farnell are sods because they even have the handling charge for trade account holders which they didn't used to. We just placed a large order with them otherwise it could have been tacked on and then you could have just covered the postage from us to you. Sorry not much help...

 

[bert]

Try rapid electronics

 

[sako243]

Or could just use findchips.com like I did

 

[minimutly]

If you replace the Igbt be sure to check the driver transistor, or whatever switches it. In my experience they never blow alone.

 

[Dr.Al]

Or could just use findchips.com like I did

octopart.com is another good one for searching multiple suppliers.

 

[Jan-DIY]

You need to change all 6 Igbt if you can not get exactly the same one because it is an 3p h-bridge.
Also check snubbers, gate resistors and buffer caps on gate driver

 

[e5c0rt.mk1]

Does anyone know how much it would roughly cost for someone who knows what they are doing to have a look at it and fix it?

Or should I just risk replacing the couple of parts and give it a try.

 

[MCKDAVID]

i'd try first, the parts cost pennies, if it doesn't work, what have you lost? time that's about it....

 

[daedalusminos]

I would remove the PCB from the heatsink so you can inspect the other side, also have a look at those two resistors - they certainly look stressed. Have you checked resistance of motor windings to each other and case?

 

[Jan-DIY]

Seems to be a common problem.

Archivio album

Don’t speak that language but he is mentioned IGBT.

 

[minimutly]

i'd try first, the parts cost pennies, if it doesn't work, what have you lost? time that's about it....

Listen to @Jan-DIY s post above, you can ignore mine, what do I know..

 

[Jan-DIY]

You are absolutely right in that Igbt often not fail alone.
That’s what I mentioned in my post of checking drivers and snubber network.
In basic these pcb is quite simple design because it is on main supply. No dc/dc converter or booster stages.

 

[MoreWellie]

go bang as soon as I plug it back in

one useful tip is to look at the fuses and replace with a bulb or resistor of a capacity that will only let an amount of the current flow, no instant bang (if you get it right!)

Edit: obviously make sure you are being safe with the connections!

 

[MCKDAVID]

Listen to @Jan-DIY s post above, you can ignore mine, what do I know..

agreed.