SERVICE NOTE SN0062

Service Note Number SN0062 Products Effected AVR500 / AVR600 Serial Number/s Effected All serial numbers

Reason For Change To replace serviceable parts that age within the amplifier section – preventative Symptoms Of Fault Bias improvement required

Description Of Change Replacement of serviceable parts Parts required 7 x bias pot, 14 x 1R resistor, 7 x 33pF capacitors - Arcam part number E434AY includes thermistors as used within SN0061 Implementation All units that come back for service

Warning **** Before removing the front panel FFC flexi foil, link place the product into standby for 60 seconds and then remove the mains lead. (at this time the Filament supply is fully discharge) and you are safe to remove the flexi foil, failure to follow this procedure will result in damage to either the front panel VFD or the HDMI board

1 Work instructions for L125AY and L196AY (upper power amp stage)

As a preventative measure, amplifier boards L125 & L129 should have the following parts replaced:

1. Bias pots : RV300, RV400, RV500 (L125AY) and RV200, RV400, RV800, RV900 (L129AY)

Arcam part number : 6F101VB Manufacturer part number : Vishay M63M101KB40 Farnell part number : 9607781

The type of pot that requires replacement is shown below:

If they are of the type shown below, they do not need to be replaced. Left example colour may vary, but should be marked 63M “100R”, right example also does not need to be replaced:

2 3 2. Fusible resistor : R329, R330, R429, R430, R529, R530 (L125AY) and R229, R230, R429, R430, R829, R830, R929, R930 (l129AY)

Arcam part number : 1G810 Manufacturer part number : BC Components 2322 205 23108 / Vishay NFR2500001008JA500 Farnell part number : 9473939

3. Feedback capacitor : C705, C803, C808 (L125AY) and C306, C310, C704, C708 (L129AY)

Arcam part number : 2D033W3 Manufacturer part number : FKP2O100331D00JSSD Farnell part number : 1519287

4. Additional testing of the thermal tracking diodes of the output devices should be carried out while the PCBs are on the bench. This can be done by measuring across the two right hand legs of the output device using a DVM in “diode check” mode. Each diode should be checked for consistency with the others, typically they will be around 470mV. If any diode reads >15mV higher, the device should be replaced.

After replacing the parts, all channels should be re-biased as per instructions below.

4 Bias adjustment *******Caution live mains risk********

Please note: it is very important that the centre channel and remaining top board presets are calibrated first before moving onto the remaining presets – calibration should be performed as quickly as possible.

1. Switch the power on. 2. Slide cover back to allow access to the preset adjustment points. 3. Set all presets to read 2mv. (rough pre-calibration) 4. Slide cover back on to touch the front panel. 5. Leave the AVR switched on with no input i/p or o/p for a period of 1 hour. 6. Slide the top cover back allowing for access to the presets as shown in fig one – now quickly locate the centre channel preset (RV400) as highlighted within fig 3 (furthest left on the top board) set this to 8mV now set to two remaining top board presets to 8mV. 7. Now calibrate the remaining four presets on the bottom board to 8mV 8. Dab a small amount of locknut or nail varnish on the pot to lock position. 9. Replace top cover.

5 PEMBROKE AVENUE, WATERBEACH, CB25 9QR. ENGLAND Telephone +44 (0)1223 203200 fax +44 (0)1223 863384 Email [email protected] Website www.arcam.co.uk

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