Mercurial > whatever / file diff

--- a/content/hp8662a.rst	Thu Nov 10 16:46:54 2022 +0100
+++ b/content/hp8662a.rst	Thu Nov 10 17:26:20 2022 +0100
@@ -44,6 +44,7 @@
 
 .. image:: {static}/images/hp8662a/dirty_hp.jpg
    :class: image-process-large-photo
+   :alt: Very dirty inside view of the HP8662A
 
 
 And I must say that if most of the unit is very easy to service due to the
@@ -54,17 +55,21 @@
 
 .. image:: {static}/images/hp8662a/top_before_2.jpg
    :class: image-process-large-photo
+   :alt: Top view of the inside of the HP8662A
 
 .. image:: {static}/images/hp8662a/bottom_before.jpg
    :class: image-process-large-photo
+   :alt: Bottom view of the inside of the HP8662A
 
 .. image:: {static}/images/hp8662a/front_after.jpg
    :class: image-process-large-photo
+   :alt: Fromt view of the inside of the HP8662A
 
 Also, there are hundreds of screws in this unit! it's insane.
 
 .. image:: {static}/images/hp8662a/top_after.jpg
    :class: image-process-large-photo
+   :alt: Top view of the many shielded compartments of the HP8662A
 
 Whatever, I finally got to a point I could clean most of the parts of the unit,
 so I started to reassemble it. Unfortunately, I did not took enough pictures
@@ -73,13 +78,15 @@
 
 .. image:: {static}/images/hp8662a/reassembling_2.jpg
    :class: image-process-large-photo
+   :alt: General view of the HP8662A case
 
-Once I had the structure of the generator back togother, with the back plane in
+Once I had the structure of the generator back together, with the back plane in
 place but no other board nor module plugged in, I started to take care of the
 PSU.
 
 .. image:: {static}/images/hp8662a/reassembling_1.jpg
    :class: image-process-large-photo
+   :alt: General view of the bottom of the HP8662A case with the main mother board
 
 The PSU
 =======
@@ -96,6 +103,7 @@
 
 .. image:: {static}/images/hp8662a/PSU_simplified_schematic.jpeg
    :class: image-process-large-photo
+   :alt: Simplified schematics of the HP8662A PSU
 
 The 4 boards the PSU is made of are:
 
@@ -116,6 +124,7 @@
 
 .. image:: {static}/images/hp8662a/PSU_block_diagram.jpeg
    :class: image-process-large-photo
+   :alt: Block diagram of the HP8662A PSU
 
 So I gave a close look at thes boards, beginning by the main board, the I found
 the culprit for the smoke: the input protection thermistor. Strangely, it still
@@ -128,6 +137,7 @@
 
 .. image:: {static}/images/hp8662a/smoking_thermistor.jpg
    :class: image-process-large-photo
+   :alt: Picture of the smoked thermistor
 
 After this first step forward, I was not confident enought to plug the boards
 back in place and try again (I am always worried when I repair switching
@@ -149,6 +159,7 @@
 
 .. image:: {static}/images/hp8662a/PSU_inverter_schematic.jpeg
    :class: image-process-large-photo
+   :alt: Full schematic of the PSU
 
 Looking at the schematics and the boards, I did find several failure points:
 
@@ -163,9 +174,11 @@
 
   .. image:: {static}/images/hp8662a/broken_choke.jpg
      :class: image-process-large-photo
+     :alt: Pictures of broken choke coils
 
   .. image:: {static}/images/hp8662a/replacement_choke.jpg
      :class: image-process-large-photo
+     :alt: Picture of the replacement choke coils
 
 - there are 2 small 400mA fuses on the inverter board to protect the base of
   the 2 switching (bipolar!) transistors (first time I see the base of an NPN
@@ -178,6 +191,7 @@
 
   .. image:: {static}/images/hp8662a/fuse_replacement.jpeg
      :class: image-process-large-photo
+     :alt: Picture of the hacked replacement fuse
 
 
 After these fixes, I reassembled the PSU and tried again: the result was quite