The Ecap is Aishi brand 4.7u 400V, checked still have about 3.9uF after >3 years use. The bulb was dim and found inside LED burnt as shown. The cause is overheat and heatsink may not good enough! This bulb save power but cannot last for 10 years!
July 1, 2021
Philips LED light bulb 6~10W type tear down photos
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hp E3612A Linear Power supply
This is a 0-60V 0.5A / 0-120V 250mA supply from hp. This is a classic design by hp for reliability and easy of use. I own this supply with input 115V version. All the component are top grade and there is nothing to upgrade! Only cleaning and re-turn the front panel meter accuracy!
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June 30, 2021
Yamaha DVD-2300MK2 SACD/DVD player
I brought this more than 10 years ago from a Canada seller. I want to try this because it use 4 pcs AD1955 DAC inside and also can playback SACD disc! Thus I want to see how does it sound. Below are the inside photos :
- Lots of Audio grade capacitor in the power supply and audio circuit. Elna Cerafine, Nichicon Muse and Copper foil capacitors for IV and Filtering in audio circuit.
- Separate digital and analogy transformer and regulators.
- DAC AD1955 x 4 with OPA2134 as IV & filter op-amp in audio output circuit. Only for SACD playback!
- PCM1608 DAC for DVD and CD playback! Thus it will not sound super good!
- Due to the age of the design, it only have S-Video and Component output for Video!
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Tektronix PS280 Power Supply RE-Cap
This is a power supply branded Tektronix but actual is OEM in Taiwan. The quality of PCB used is not that great as it is using fibre board. Spec of this supply is two output with 0-30V 2A and one output 5V 3A. This supply was made more than 20 years ago and the casing and some screws are already getting little rusty! All e-cap are make by Jamicon!
- Big capacitor is changed from 4700uf 63V to 6800uf 63V. Use Rubycon.
- 470uF 35V to 560uf 35V, 100uF 25V use same but all Panasonic FC grade in filtering section board.
- Control board two 47uF change to Nichicon; 4.7u change to 12uf x 2 Pana FC. 6800uf 25V to 10000uF 16V, rubycon.
- Display control board for supply filtering change 1000uF to 2200uf Pana FC grade. 100uf use same value.
- The fan supply board also upgrade two capacitor to Panasonic FC grade.
- After that I follow the service manual do adjustment/verification and the set is found within 0.1V/0.1A accuracy. Thus I can say even an OEM product branded Tektronix also very stable for over 20 years life time!
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June 28, 2021
hp 3324A functional generator service and repair
The equipment also have RIFA cap and thus cleaning and service is needed.
- Some inside photos.
- Changed all 3 RIFA capacitors as they have body crack.
- This set come with precision time base 10Mhz clock but the clock do not look very square wave in scope. Jitter is about 30ps, not the best in class.
- The battery inside still above 3.2V after >25 years.
- After assembly back, found the output amplitude is not able to set within 1 to 10V, thus there is an issue with the amplifier section which need further trouble shoot! Frequency setting is fine.
- The problem on this sig gen was identified as the power switch one side open circuit at power ON position. Fixing the power switch and the signal gen is back to normal.
Main board 
Output section, relays 
Rear side 
High level o/p option 
Battery is still above 3V 
Transformer 
X2 and Y capacitor see crack issues 
X2 and Y caps replaced 
Case is clean with WD-40 
10Mhz option 
The two connected pins is OPEN when the switch is pressed at ON position.
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