Temp R204

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16-Oct-2019 06:32 PM

apper

apper

Posts: 7

Am checking the PSU board and noticed that R204 gets to hot to touch. Is that too be expected ?

Measured 55V and 0.74 mA = 40mW

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23-Oct-2019 11:54 AM

Stefaan

Stefaan

Posts: 618


What Quad is this about?

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23-Oct-2019 12:05 PM

apper

apper

Posts: 7

303, checked up on previous forum posts, is to expected.

just get's too hot to touch by hand (finger..)

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23-Oct-2019 12:56 PM

Stefaan

Stefaan

Posts: 618

Yes, indeed, R204 in the 303 power supply is getting hot, that's normal.

For this reason it should be mounted a few mm above the circuit board.

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11-Nov-2019 11:54 AM

Hugues

Hugues

Posts: 2

If you look in the service manual available in the downoad section, it seems like Quad changed the value of R204 from 10K to 6K8 (look in the part list).

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11-Nov-2019 03:32 PM

apper

apper

Posts: 7

Correct, changed mine to 6K8. And some heatsink to R204 and R205, just to make shure.
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12-Nov-2019 02:11 AM

EJP

EJP

Posts: 1669

> Measured 55V and 0.74mA

Impossible. 55V across 10K ohms is 0.0055A, or 5.5mA, which in turn is 0.3025W, which is why it feels hot, and why you should use a resistor rated at at least 0.6W in this position. A 6k8 resistor will yield 8mA and 0.444W.

I wouldn't be in any hurry to change it to 6k8. 10k works fine, and less heat.

EJP

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12-Nov-2019 08:47 AM

apper

apper

Posts: 7

Yup, correct, the mA was wrong.

Why then 6K8 as stated in service manual?xfhqed

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12-Nov-2019 09:44 AM

EJP

EJP

Posts: 1669

No idea. I've never used anything but 10k in nearly 15 years.

EJP

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